Holder changer

ABSTRACT

A holder changer includes a robot fixed to front or rear faces of a press, and an oblique elevator which obliquely moves a plurality of holders to a work moving level from a lower level in a direction crossing a work moving direction. A fixing portion at an end of the robot is adapted to removably hold and transport the holders for changing the holders.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a holder changer, and in particular toa holder changer for automatically changing holders, which are used totransport materials or works to a press and to transport the machinedworks from the press, in accordance with types of the materials andconfigurations of the works.

2. Description of the Background Art

In tandem presses, holders of transportation robots have been changedeach time the specification for the work is to be changed. This changingoperation is carried out by an operator, who enters a central section ofa transporter, and the press is stopped during this operation.Therefore, in the press industries which have been required to complywith production of various types but small number of products in recentyears, a frequency of change of the holders of robots necessarilyincreases, which increases the stop time period of the presses,resulting in reduction of the press productivity. Further, since thechange of the holders is manually carried out, sufficient measures forachieving the safety of the operator must be applied to the press andperipheral equipments, resulting in increase of the expenses for theequipments and persons.

An object of the invention is to provide a holder changer capable ofautomatic changing of holders used for transporting materials and worksin a press operation.

Another object of the invention is to provide a holder changer whichrequires a press to be stopped only for an extremely short time period,allows an operator to stay at a safe position remote from a centralsection of a transporter, and enables change of holders without stoppinga press line, e.g., conveyor.

SUMMARY OF THE INVENTION

The present invention provides a holder changer including a robot fixedto front or rear faces of a press, and an oblique elevator whichobliquely moves a box for bearing a plurality of holders to a workmoving level from a lower level in a direction crossing a work movingdirection, wherein a fixing portion at an end of the robot is adapted toremovably hold and transport the holders for changing the holders.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section taken along line I--I in FIG. 6, showing acondition in which a holder changer according to the invention isextended for a changing operation;

FIG. 2 is a cross section taken along line I--I in FIG. 6, showing astandby state of a holder changer according to the invention prior to achanging operation;

FIG. 3 is a cross section taken along line III--III in FIG. 1;

FIG. 4 is a cross section taken along line IV--IV in FIG. 6;

FIG. 5 is a side view of a whole layout shown in FIG. 6; and

FIG. 6 is a plan view showing a whole layout of an embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 6 shows a layout of an embodiment of the invention, in whichpresses indicated by reference numerals 10, 20 and 30 are disposed intandem with conveyors 7 therebetween. At numerals "201" are indicatedoblique elevators, which are holder changers according to the invention."5" and "8" indicate feed and discharge conveyors, respectively. FIG. 5is a side view, in which "11" and "13" indicate robots fixed at frontand rear faces of the press 10, respectively. "21" and "23" indicaterobots fixed at front and rear faces of the press 20, respectively. "31"and "33" indicate robots fixed at front and rear faces of the press 30,respectively. Further, "1" indicates an upper die of a press die setprovided at each press, and "2" indicates a lower die of the press dieset. "4" indicates a material stack. For example, when the press isoperating, a first movable base 210 of an oblique elevator 201 as wellas a second movable base 211 to which a box 200 is fixed are located ata right position, i.e., standby position, as shown in FIG. 2, and anoperator loads a holder 25 on a lower deck of the box 200. After therobot 23 transported a work 111 from the press 20 onto the conveyor 7,as shown in FIG. 4, and the conveyor 7 transported the work 111, ageared motor 203 (see FIG. 3) is turned on, whereby the first and secondmovable bases 210 and 211 extend leftward to the position shown inFIG. 1. Simultaneously, a support elevator 220 rises to a position inwhich a connector 221 at the end of the elevator 220 is connected to aconnector 213 at the end of the second movable base, whereby the movablebases 210 and 211 in a cantilever form are firmly supported by a supportelevator 220.

Now, description will be made on a mechanism and an operation for movingthe first and second movable bases from the standby position in FIG. 2to the extended position in FIG. 1 and for returning the first andsecond movable bases from the extended position to the standby position.In FIG. 1, a rack 206 is fixed to the upper surface of an inclined base205. A first pinion 207 rotatably supported by the first movable base210 is in engagement with the rack 206. A rotary force of a rotaryshaft, to which the first pinion 207 is fixed, is transmitted through apulley and a toothed belt 212 to a second pinion 208. The second pinion208 is rotatably supported at an upper left portion of the first movablebase 210, and is in engagement with a rack 216 fixed at the lowerportion of the second movable base 211. Therefore, when the geared motor203 drives its pulley counterclockwise, a connector 209 fixed to a chain204 moves leftward and upward to move the first movable base 210 in thesame direction. As a result, the first pinion 207 is driven, and therotary force thereof is transmitted to the second pinion 208, wherebythe second movable base 211 is moved leftward and upward at the samespeed as the first movable base. Therefore, the speed at which thesecond movable base 211 moves with respect to the ground is twice aslarge as the speed at which the first movable base 210 moves withrespect to the ground. Accordingly, the holder 25 on the box 200 movesfrom the standby position to the change position (extended position) atthe double speed owing to the double deck structure, and thus the timeperiod required for changing the holders is reduced. Further, in thestandby state, the structures are retracted to be compact, so that anarea occupied by the installation can be small. The movement from theposition in FIG. 1 to the position in FIG. 2 is carried out in theopposite manner.

The second holder 25 to be changed is loaded on the lower deck of thebox 200 when the box 200 is in the standby position in FIG. 2. Then, thefirst and second movable bases 210 and 211 extend to the position inFIG. 1, and the robot transports the used first holder 25A onto theupper deck of the box 200 and leaves the first holder 25A.

Then, a pneumatic fixing portion 101 of the robot 23 firmly holds thesecond holder 25, and temporally maintains the second holder 25 at aposition above the box. Then, the first and second movable bases returnto the standby position, and the support elevator also lowers to theposition shown in FIG. 2. Thereafter, the robot in the temporarilystopped state is reactivated to start the second work transportingoperation. During the pressing operation, the operator loads and unloadsdifferent tools in and from the box, if necessary, which is located atthe standby position remote from the central section of the transporter.The robot, conveyor and oblique elevator are controlled by acontroller(s) installed around the main body of the press.

Electrical interlock is provided between the operations of the robot 23and the oblique elevator 201 to prevent the mutual interference. Theseoperations are controlled in accordance with a program sequence whichhas been prepared in advance.

The holders in the illustrated embodiment may be vacuum holders eachprovided with many suction cups, and also may be other types of fingers.

The present invention can achieve all the objects described before.Specifically, in a preparatory operation which can be done during theoperation of the press, the new holder may be loaded in the supply box,whereby the holders may be automatically changed when the press workingis completed, so that the operation rate of the press is improved. Also,the safety for the operator is improved.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

What is claimed is:
 1. A holder changer apparatus for changing a holdermeans for transporting raw works to a press and for removing machinedworks from said press, said apparatus comprising:an elevator meansadjacent to said press for delivering a plurality of said holder meansfrom a standby position remote from said press to an extended andelevated position proximate said press; robot means mounted on saidpress for selectively receiving at least one of said plurality of saidholder means from said elevator means; a fixing portion provided on saidrobot means, for removably carrying said holder means.
 2. The holderchanger apparatus according to claim 1, further comprising a conveyormeans for conveying said raw works and said machined works in a workmoving direction, wherein said elevator means obliquely moves withrespect to said work moving direction from said standby position at alower level to said extended position at a work moving level.
 3. Theholder changer apparatus according to claim 1, wherein said elevatormeans comprises first and second movable bases and a box means forcontaining said holder means, said first and second movable basesadapted to move in a telescoping manner from said standby position tosaid extended position.
 4. The holder changer apparatus according toclaim 3, wherein said first movable base comprises first and secondpinions, said first pinion engaging a first rack provided on a fixedinclined surface, and said second pinion engages a second rack providedon said second movable bases.
 5. The holder changer apparatus accordingto claim 1, further comprising a support means for providing additionalsupport to said elevator means at said extended position.
 6. The holderchanger apparatus according to claim 1, wherein said press passesthrough a press work area during a pressing operation, and said elevatormeans extends within said press work area at said extended position. 7.The holder changer apparatus according to claim 1, further comprisingcontrol means for simultaneously controlling said robot means and saidelevator means.
 8. The holder changer apparatus according to claim 1,further comprising an interlock means provided between said robot meansand said elevator means for preventing mutual interference thereof. 9.The holder changer apparatus according to claim 1, wherein said holdermeans comprise suction cups for gripping said raw works and saidmachined works.